Designing a Better Laboratory Course

by Richard Keith Slotkin, Plant and Microbial Biology

Teaching Effectiveness Award Essay, 2005

I encountered my first teaching problem months before entering the classroom. While reading through past student comments from the laboratory class I planned to teach, I noticed two recurring criticisms. The complaints addressed both course structure and time management. Since many of the laboratory exercises were longer than the three hours of lab time provided each week, the course dictated that students work on parts of several laboratory exercises in one class session. For example, students would start growing plants for laboratory 5, isolate DNA for laboratory 3 and collect data for laboratory 2 all within one class period. Many students were disgruntled with this laboratory structure because they were never able to focus on and complete an entire exercise in a single class session. This left the students feeling a lack of accomplishment, and it was difficult for them to piece together complex ideas. Further, the laboratory work often ran ahead of the corresponding concepts covered in the lecture course. Students felt that they were simply going through the motions and not fully comprehending their actions and the associated concepts. Before the semester started, I felt that this was an obstacle to student learning. I decided to redesign the laboratory course structure to manage class time more effectively and to correspond to the lecture course.

Before the semester began, I created entirely new laboratory exercises. I emphasized finishing one project before starting another, and staying focused on what was being concurrently taught in the lecture course. For many laboratories, the protocol could not be completed within the allotted class time. Therefore, I set up what I called “cooking show” exercises. For example, when a student finished assembling a reaction, instead of waiting for a week to see the results, I had pre-run reactions ready. This enabled us to bypass time intensive waiting steps and allowed the students to complete long protocols within the three-hour class time. However, I also realized that the students would want to see if their own reactions were successful. I always completed the rest of the protocol with their samples at all points in which they swapped their samples for prepared ones.

In the next class period, I would then show them the result of their own experimental samples. I felt my new method had two advantages. First, the ability to complete long lab protocols within one class period meant that the lecture course would always correspond to the laboratory concepts the students were learning. Students did not need to start upcoming labs weeks before they had been introduced to the corresponding theories. Second, students did not feel cheated by my prepared samples because I always made sure to finish their reactions at all points throughout the protocol. The students were very interested when I showed them the results from the samples they had set up the previous week. If a student’s reaction worked, I let them choose between their reaction and my prepared samples as the data source for their laboratory reports.

I was able to gauge the success of my change in course design several ways. First, my new methods addressed the issue of time management by effectively completing five-hour protocols within three-hour class sessions. The laboratory exercises I created ran smoothly, part of which I attribute to my teaching of concepts that were simultaneously being taught in the lecture course. Second, I polled the students several times to see how they felt about the style changes I implemented. I was prepared to revert to the style of previous years if the students desired, but they insisted that this teaching style was effective. I was also able to assess my new course organization by speaking with the professor of the lecture course. He informed me that this year was much easier for him to teach than years past. Due to the new laboratory format, the students were better able to integrate and connect information from the lecture and laboratory courses. Finally, the students commented on the structure of the laboratory in the end-of-semester course evaluation. The response to my laboratory class design was overwhelmingly positive. With this feedback, I am confident that I achieved my objectives of improving the educational value and time management of this laboratory course.